The invention relates to an underfloor wheel set barring machine for retreading the rim circumferences of railroad wheel sets, with two driven pairs of friction rollers which can be pressed against a rim circumference of a wheel set, with the friction rollers of each pair of friction rollers being pivotable singly around a pivoting axis each arranged parallel to the axis of the wheel set.
In an underfloor wheel set barring machine according to French Patent No. FR-PS 1269726, each pair of friction rollers is driven by two rotary driving means, each of which consists of a geared engine and a universal joint shaft.
Such rotary driving means for a pair of friction rollers are relatively complex.
It is an object of the present invention to provide a rotary driving means for each pair of friction rollers of an underfloor wheel set barring machine of the type named above, which driving means can be manufactuerd simply and with less effort.